EGR Code HELP

[Tet97Chev]

Picked up my '98 Z71 last week and its been throwing a code for the EGR. Thinking the valve had gone bad, I replaced the valve and go figure it throws another code within 5 miles of replacing it.

This time it was the P1404 EGR 2 code... I've done some research and everything I can find suggests reprogramming the PCM to clear the code.

How do I go about doing this?? May sound like a stupid question to some but I have absolutely zero experience with the PCM on these trucks.


Thanks!

 

[Tet97Chev]

Figured out this code is from the EGR being stuck either open or closed. Anybody have any ideas as to what would cause this??

 

[east302]

The computer is seeing that the EGR valve pintle is not going to the preset closed position. It will command the valve open to try to clear any obstruction in the valve and, after three failed attempts, will set the code.

You may just have a bad new part but, if you didn't clear the code when it was replaced, the VCM is using the old (malfunctioning) pintle position as the basis and is triggering the code.

Clear the DTC using a scanner and see if it comes back.


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[Tet97Chev]

The computer is seeing that the EGR valve pintle is not going to the preset closed position. It will command the valve open to try to clear any obstruction in the valve and, after three failed attempts, will set the code.

You may just have a bad new part but, if you didn't clear the code when it was replaced, the VCM is using the old (malfunctioning) pintle position as the basis and is triggering the code.

Clear the DTC using a scanner and see if it comes back.


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I didn't see what the original code was when I took the truck in to have it checked, but my mechanic had said that it was an EGR - 1 code, so we replaced the EGR and less than 5 miles down the road the light came back on and now we ended up with the P1404 EGR - 2 code. Do you think resetting it again is going to get rid of the problem or is there something else that could be causing the issue?

 

[east302]

I would try clearing the code first (autozone or someone like that could do it for free) and see if it comes back. The computer needs to relearn the valve position with the new part.

If the code comes back, it could be a wiring issue where the VCM isn't communicating correctly. I can pass on the diagnostic tables for that if you need it.


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[Tet97Chev]

I would try clearing the code first (autozone or someone like that could do it for free) and see if it comes back. The computer needs to relearn the valve position with the new part.

If the code comes back, it could be a wiring issue where the VCM isn't communicating correctly. I can pass on the diagnostic tables for that if you need it.


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That would be great if you could. What's the best way to pass those along? Are you able to do it over the forum or should I PM you my email?

 

[east302]

Here you go, it's for a 1998 350. Looks like you'd need a pretty decent scanner to command the EGR valve into certain positions...

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[Tet97Chev]

Really appreciate that! My mechanic has a SnapOn scanner so I've got no doubt he'd be able to do it if I brought him the table. I'm going to start by resetting the code first and see if it comes back. Thanks again for your help!